e antigen has been shown to be an excellent marker to define those HBsAg-positive individuals most likely to transmit hepatitis B. Implicit in this statement is the fact that e antigen-positive health workers and patients will carry an additional stigma and may be placed under more stringent restrictions than HBsAg-positive individuals who are e antigen negative. Before any such decisions can be rendered, it must be ascertained if the presence or absence of e antigen is an invariant feature of any given HBsAg-positive individual or if it varies over the course of time.